Tagged Questions

Quantum information is the study of the informational content of quantum states. The most common object of study is the "qubit", the information in a two-state quantum system such as spin-1/2 or photon polarization.

We need non-abelian fractional hall states because of the ground state degeneracy
http://rmp.aps.org/abstract/RMP/v80/i3/p1083_1 (arXiv version for free). But we can also have degeneracy even in case ...

Background :
I am reading the paper device independent outlook on quantum mechanics. The author mentions the concept of two pure states being equivalent up local isometry. From what I understood two ...

Looking at the links below, could somebody please explain how entanglement between Alice and Bob particles is established/deduced from Victor's choice/measurement? I understand that Alice and Bob can ...

Suppose I want to calculate the maximum of Bell inequality for three parties system. In this case I will have 6 measurement directions (unit vectors). It has been done in the paper PHYSICAL REVIEW A ...

What, exactly, makes the toric code a quantum error-correcting code as opposed to any other string-net model? What makes it special? The way I understand it, it's a normal string-net model on a torus, ...

I do know how Bell states look like. They can be distinguished by doing a Bell measurement. A measurement has 4 possible outcomes (as there are 4 states, which form orthonormal basis). However I have ...

Suppose Alice creates a secret n-qubit state $\lvert \psi \rangle$ from a description $d$, and gives the states to Bob. (Bob doesn't know $d$ )
Bob who doesn't trust the channel, wants to verify if ...

Does Gödel's Second Incompleteness Theorem imply that no Theoretical Physics model of reality can be proved to be consistent using the laws of physics?
I work partially in Quantum Information Theory ...

Could anyone point me in the right direction (reference to papers would suffice) regarding the following:
Given two quantum states $|\psi\rangle ,|\phi\rangle \in (\mathbb{C}^d)^{\otimes n}$, where ...

What it is in basic particles that make them propagate themselves through time or, basically, what brings that property known as Duration in a particle (wave)? I sense that this is somehow is based ...

Of course it is expected. But how to prove it analytically?
Slater determinant is mentioned in almost every quantum mechanics textbook. But it is necessary to warn the undergraduate students that not ...

Assuming it is possible in principle to entangle the degrees of freedom of the event horizons of two black holes, and that this is something that can be done, either after the black hole is formed, or ...

What is a spatial profile for a wavefunction of a superconducting qubit (such as say a flux qubit, charge qubit, or a transmon)?
I am trying to calculate the energy shift of an superconducting qubit ...

Long storage times for qubits will be integral in the construction of a scalable quantum computer. This leads me to ask the current state of affairs in our ability to store qubits. Namely, what is the ...

apart of the 't Hooft diagrams that you all love (and find all sort of dualities starting with them) one of the venues 't Hooft works nowadays is apparently some sort of "deterministic representation ...

I'm interested in Type 1.5 superconductors, first proposed by Egor Babaev in 2002 and found in the laboratory in 2009 (magnesium dibromide). Such conductors favor small bundles of vortices. The most ...

I'm given a one-dimensional potential with two wells, one local minimum at some higher energy and one deep global minimum next to it, separated by a barrier of own shape and height (phase qubit). I ...

In a paper by Richard Josza and Noah Linden they argue that the way state spaces of composite systems are formed is a key aspect in the benefits of quantum computers. In (classical) phase space, two ...